What is cryptography?Cryptography is the study of making information secret it has existed for many thousands of years and different people have used it for different reasons.Information would usually be a message consisting of words numbers and letters.by secret it means it is only intended for the person who is writing it or receiving it but if anyone else was to steal it they would be unable to read it.An example of this would be if Alice and bob were to split up and there was no way to communicate they would need a way to send private messages from a distance.The only way to do this would be ciphers because if you used a lock and tried to send something anyone could intercept the message.But if you use ciphers wich means scrambling the letters.If someone was to intercept it then it would not have a meaning.This is how code breaking started as to what it is now in the modern day and age.One of the most common and easiest cipher would be the caesar cipher wich would go back thousand of years.The main two functions of a cipher is to encrypt the message or decrypt it we do that by changing words to get an encrypted message and then getting the encrypted message and decrypting it to get its original form What is a caesar cipher?A form of substitution cipher is when each of the letters in the alphabet is replaced with the letter being certain numbers of places ahead of it near the end of the alphabet you re-wrap and start from the beginning .The ceaser cipher may shift the letters any number of places.the ceaser cipher is like the other substitution ciphers and is simple and easy to use.the person receiving this can remember the shift.However this is very simple and can be intercepted by an enemy. The man who invented this was julius caesar who found it in 58 bc. This is one of the easiest cipher codes and many people in this day and age could crack it .caesar invented this code so a enemy could not intercept this.He would do this by switching letters which would be meaningless making the enemy confused the way he would do it is he would write a message for instance “MEET ME AT ANARCHY ACRES” so you had a simple message but before the message is sent you would send the other person a key this would be a shift so you could have any shift from 1-25 so if it was three the word MEET would turn into PHHN This looks like gibberish but if an enemy found it he would not know the meaning this was used for a long time until a man by the name of AL-Kindi intercepted it 800 years after it was released it was intercepted by something called frequency analysis this was major for the start of cryptography and code breakingWhat is The vigenere cipherThe vigenere cipher was a very complicated but efficient cipher it was named after blaise de vigenere in 1553.The vigenere cipher uses 26 different cipher alphabets each a version of the caesar cipher and a random keyword.The keyword is written along the message and is repeated until they are the same length apart so the amount of letters in the alphabet are 26 so the keyword has to be 26 long so it would be 26×26 leaving you with 676 boxes.The more longer the keyword was the harder it would be for someone to de encrypt it.To encrypt the message you would write out the message at the top with 26 letters without spaces and the keyword on the side For example if we were using the message FORTNITEISCOOL and the keyword as MONKEY the final message would be RCFD etc This made it hard because if you connect M to the letter F it comes with R so if you keep on doing that it will give you the message and then you can send it to someone.The good thing with vigenere cipher is that it is immune to frequency analysis and other methods to attack monoalphabetic ciphers.It was not until the nineteenth century when someone finally found a way to counter the messages.What is an enigma machine As the vigenere cipher was defeated and radio being the new way to communication.the next step in communication came in the twentieth century in cipher machines as they wanted machines faster than human or pen also one that produced fewer errors and too complicated methods the most famous was the enigma machine.It is basically a keyboard connected a series of electrical and mechanical switches.when a letter on the keyboard is pressed a different letter will light up on the screen.Also the enigma machine could de encrypt a encrypted message.the enigma machine had vast amount of settings which were complex everytime the machine was used it could be changed the only effective way of attacking was brute force even with that and all the settings it would take too much time and the enigma was known as unbreakable .After some mathematical tricks which lowered the enigma settings. the enigma was broken which drastically changed world war 2 this was done by a famous cyprotghpaer of britain and mathematician alan turing he did this by inventing a machine called the bombe this is eventually how they had found out adolf hitler had commit suicide so behind one computer britain won the world war because if they didn’t intercept their messages they would not what was going onWhat is Binary codesAfter the war computers became really popular and a lot of people would buy them but also they were very simple everything we do like counting the computer would have to be taught step by step this was achieved by a system called binary.Binary could only read the number 1 or 0 no other way behind everything is numbers and they are only 1 and 0 we cannot simply ask the computer to add 1+1 we must note the binary sum so it cannot come with the number 0 because it is only taught the number 1 and 0 so instead of using the plus sign they would use something called XOR which is basically a circle and a plus in the middle The simple numbers would be 1 XOR 1 =0 the answer would be 0 because it cannot do 2 so it would take it away to create the number 0 it is like odd + even would be odd.This was the way computers worked What is morse code The morse code was developed so messages could be sent down wirees and just like computers they could register whether the current was on or off so long dashes and full stops modern computers use a method called the american standard code for information interchange.where every character is assigned a seven digit binary number so seven binary numbers can count upto one hundred and twenty eight.This would mean that any seven figure per letter message can be much longer than written in english.For instance a simple message such as hello is the number 10010001000101100110010011001001111 but computers are very good using the numbers 1 and 0 so they can transfer them rapidly and accuratelyWhat is the one time padThe strength of the vigenere is good but its weakness is the fact that it only cycles once through fixed set of cipher alphabets which it repeats.this repetition can be exploited through ceyptanslayts to guess the cipher keyword and break the encryption.having no repeating patterns is the key to the one time pad method.this is the way to encrypt binary numbers For example if their message to be encrypted is some binary numbers 1000110 to encrypt it with the one time pad and for that you need a key which is a random binary number the same length as the message 1101110.To encrypt it we take the binary sum of each figure in the message with its corresponding figure in the key.since the key is random their will be no pattern left for the catrynpals to exploit.the only other way is to brute force attack meaning testing every single key.and with this the attacker will reveal all the messages not knowing which message is wichWhat is RSA encryptionRsa encryption name after ron rivest adi shamir and leonard adleman is a currently used public key cryptosystem which relies on prime factorisation .The first system was first described in 1978.The rsa algorithm uses a function which makes it able to enycprt a number using public/encryption key in such a way that it is difficult to compute the reverse function unless you know the de encryption key.It can easily be done if you know the prime factors of the key What is password hashing